How to research a lake before fishing a trout derby.

From time to time I get asked for advice on the best way to approach fishing a trout fishing derby or competition. Those who ask, are more often than not fairly new to the sport of fishing, or at least new to the lake where the competition is due to take place

It can take a lifetime to learn all the secrets of a trout fishery, but I feel a lot can be learnt about a lake without even fishing it. In this article, I am going to share how I research a lake I have never been to before.

I am going to be describing a real lake (Lake A) but will avoid idenitifing it to avoid spot burning. Nevertheless, it is quite a well known lake.

1) Figure out what lives in the lake

The first question, I want to know the answer to is what type of trout live in the lake. Are they stock trout, wild trout, or holdover trout? Are there only rainbow trout in the lake, or maybe there are some browns, cutthroat, or even brooks?

If fishing in a derby, most released stock trout are nearly identical in size. Sometimes, the organizers might include brood stock or larger fish but hooking up to one of them, rather than a 10″ stock trout is mostly a game of chance. If they live in the lake, I much rather spend my time trying to catch a holdover or wild fish because chances are they will be much larger.

If the fishery does not support holdover fish, or if the derby is targeting a tagged ‘stock fish’ then of course. I will have to target the stock trout.

In the case of Lake A, a quick google search reveals that the lake is home to both rainbow and brown trout, with fish up to 8lb being caught. This suggests to me that older holdover (or wild) trout are in the lake.

Knowing that the lake does indeed have mature trout, I will target them directly in the hopes of getting the largest trout on the day.

2) Any Bass or aggressive predators?

If it is only a stock trout fishery, I will also check if there are predatory fish in the lake such as bass. It is well known, that stock trout are often chased into the shallows where they find protection under structures close to shore.

The other fish species present in the lake might provide some idea of where trout are more likely to be found.

In the case of Lake A, there are no Bass. But there are large brown trout, and I am fairly certain a big hungry Brown will certainly try to eat a disoriented 10″ rainbow. This might actually be a problem, one stock trout is a very large meal even for the largest of trout. If they decide to attack and eat the stock trout, they probably will be busy digesting it and will be extremely difficult to catch.

In saying that, I have caught brown trout with full stomaches before, and they were greedy enough to strike my lure. So even a full trout might not turn down an easy meal.

3) Figure out the water temperature

I want to know how warm the water is, if the water is too warm chances are the trout will be holding deep, and only approach the shallows in the evenings when the water temperature starts to cool.

Sometimes I will check the weather, but in the case of Lake A, the lake water temperature is published online. It is currently 61f, which means the trout should be feeding throughout the day, and will not be seeking refuge in deep water.

If the water temperature was over 68f, I will have to make plans to fish deeper water.

4) Load Google Earth and check the layout

I want to know what the lake looks like. I want to try and identify shallows, river deltas, or anything that might give me an edge.

I also want to know how accessible is the lake, is it possible to walk around, or would I need a boat.

One of the best tools for this job is google earth, I prefer earth over google maps because it has measuring tools built in. By quickly measuring features it gives me a better idea of scale and what is fishable from where.

Lake A

Access and parking

There is a hiking trail that loops around the lake, meaning the entire shoreline is accessible from the shore. There is very little road access, mostly just a parking lot and a little side road that looks like it ends at a trailhead.

Inlets and outlets

I immediately noticed there is a named creek that feeds the lake, and one outlet drains it.

The feeding creek is quite large, with a strong flow. While an excellent spot, boats are going to crowd it on derby day. I even count 5 boats fishing it on google maps.

The outlet is right next to the parking lot and boat ramp, it likely will see heavy fishing pressure so not a place I want to fish on derby day. By the looks of things, the boat ramp probably will be where the stock trout are released.

More interesting, there seems to be three shingle gulleys. While they are not flowing, each one has deposited a small delta which is mostly surrounded by deeper water. They look large enough to hold trout but small enough to escape too much attention.

Flats and drop-offs

The northern shoreline is dominated by shallow flats, these stretch out between 70-100ft before dropping away. So, on that side, I can fly fish the flats but will need a boat to fish the drop-offs.

The western shore is where the marina and boat ramp is. There is also a very large flat that stretches out some 200ft. It probably will hold trout, but it could be hard casting without spooking them. Maybe better for spinning tackle.

The eastern shore, is the delta of the feeding stream, a bit surprisingly, the drop off is only 35-50ft from the shore making it within range of land fly fishing.

The southern shoreline has even fewer shallows, with the drop off some 30ft. As a land-based angler, I will concentrate on the southern shoreline, because I can fish both the drop-off and shallows.

5) Check for marine charts

After checking google earth, I normally look for a marine chart or nautical map and quickly glance over it. These are useful to give the depth profile of the lake and can be used to identify underwater structures.

In the case of lake A, I was able to find a chart.

The ‘floor’ of the lake seems to be 120ft, with one deep hole down to 140ft. All the sides are quite steeply sloping, and there are several underwater bluffs. None of which will be of much interest for me if fishing from the shore.

The bluffs seem to start at around 40ft and drop down to 100-120ft. In my experience, brown and rainbow trout do not usually hold around deep water bluffs. I doubt there is much food down there to interest them. I probably will just make a note of their location and might drop a few jigs down if desperate or if there is a good sign of the sounder.

6) Putting everything together and making a plan

Finally, I will try and figure out how best to take advantage of my recently gained knowledge.

In wild trout fisheries, I will usually target wild trout and not the recent stock fish. For this reason, I am more likely to be fishing flies, streamers, and maybe spinners. I will leave the corn in the cupboard, and the powerbait in the shop.

I will concentrate most of my effort on the drop-offs that I can reach from the shore, but if the lake is busy. With many boats, I might start concentrating on the extreme shallows which are less accessible by boat anglers casting in.

If the tournament goes for longer than a day, and If I am motivated enough to try and place. If regulations allow I will be tempted to night fish live minnows suspended above the dropoffs. I might also target the outlet creek with large streamers in the early hours of the morning.

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